Sterile medical liquid containers are used to dispense liquids in various medical procedures. One type of container, called a "pouring" container, is used to dispense sterile liquid to a surgical site. Here the physician may pour liquid from the bottle into the surgical wound to cleanse the wound. Another type of medical liquid container is connected to a tube and suspended above the patient to dispense irrigating liquid to a precise site, such as in a transurethral resection procedure. Still another type of medical liquid container is used for the administration of parenteral solution into a patient's vein.
All of these sterile medical liquid containers have a common purpose of maintaining the sterility of their liquid contents during storage, shipping and dispensing. An extremely critical portion of these containers is their closure system. The closure system must maintain a bacteria-tight seal until intentionally opened. All of these closures must be easy for the nurse or physician to open.
One means of providing a bacteria-tight seal in a container closure is to make the closure an integral part of the container. This can be done by forming the container enclosure as a one piece unit such as blow molding, or the closure can be fused or bonded to the container. To open the container a frangible or separable portion of the closure or bottle is broken or torn. Considerable difficulty may be encountered in maintaining the precise control of wall thickness, material formulation, and manufacturing conditions necessary to achieve proper separability. If the frangible section is too thin it increases the chance of a pinhole and contamination. If the frangible section is too thick it is difficult to open. Also with some of these containers the frangible section leaves a ragged pouring or dispensing lip which could shed particles into the sterile liquid.